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/* blast.h -- interface for blast.c |
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Copyright (C) 2003, 2012, 2013 Mark Adler |
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version 1.3, 24 Aug 2013 |
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This software is provided 'as-is', without any express or implied |
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warranty. In no event will the author be held liable for any damages |
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arising from the use of this software. |
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Permission is granted to anyone to use this software for any purpose, |
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including commercial applications, and to alter it and redistribute it |
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freely, subject to the following restrictions: |
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1. The origin of this software must not be misrepresented; you must not |
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claim that you wrote the original software. If you use this software |
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in a product, an acknowledgment in the product documentation would be |
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appreciated but is not required. |
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2. Altered source versions must be plainly marked as such, and must not be |
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misrepresented as being the original software. |
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3. This notice may not be removed or altered from any source distribution. |
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Mark Adler [email protected] |
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*/ |
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#define local static /* for local function definitions */ |
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/* |
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* blast() decompresses the PKWare Data Compression Library (DCL) compressed |
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* format. It provides the same functionality as the explode() function in |
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* that library. (Note: PKWare overused the "implode" verb, and the format |
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* used by their library implode() function is completely different and |
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* incompatible with the implode compression method supported by PKZIP.) |
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* |
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* The binary mode for stdio functions should be used to assure that the |
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* compressed data is not corrupted when read or written. For example: |
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* fopen(..., "rb") and fopen(..., "wb"). |
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*/ |
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typedef unsigned (*blast_in)(void *how, unsigned char **buf); |
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typedef int (*blast_out)(void *how, unsigned char *buf, unsigned len); |
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/* Definitions for input/output functions passed to blast(). See below for |
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* what the provided functions need to do. |
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*/ |
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int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow, |
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unsigned *left, unsigned char **in); |
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/* Decompress input to output using the provided infun() and outfun() calls. |
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* On success, the return value of blast() is zero. If there is an error in |
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* the source data, i.e. it is not in the proper format, then a negative value |
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* is returned. If there is not enough input available or there is not enough |
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* output space, then a positive error is returned. |
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* |
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* The input function is invoked: len = infun(how, &buf), where buf is set by |
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* infun() to point to the input buffer, and infun() returns the number of |
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* available bytes there. If infun() returns zero, then blast() returns with |
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* an input error. (blast() only asks for input if it needs it.) inhow is for |
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* use by the application to pass an input descriptor to infun(), if desired. |
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* |
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* If left and in are not NULL and *left is not zero when blast() is called, |
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* then the *left bytes at *in are consumed for input before infun() is used. |
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* |
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* The output function is invoked: err = outfun(how, buf, len), where the bytes |
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* to be written are buf[0..len-1]. If err is not zero, then blast() returns |
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* with an output error. outfun() is always called with len <= 4096. outhow |
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* is for use by the application to pass an output descriptor to outfun(), if |
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* desired. |
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* |
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* If there is any unused input, *left is set to the number of bytes that were |
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* read and *in points to them. Otherwise *left is set to zero and *in is set |
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* to NULL. If left or in are NULL, then they are not set. |
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* |
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* The return codes are: |
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* |
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* 2: ran out of input before completing decompression |
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* 1: output error before completing decompression |
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* 0: successful decompression |
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* -1: literal flag not zero or one |
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* -2: dictionary size not in 4..6 |
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* -3: distance is too far back |
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* |
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* At the bottom of blast.c is an example program that uses blast() that can be |
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* compiled to produce a command-line decompression filter by defining TEST. |
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*/ |
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